Response to Intervention: Empirically Based Special Service Decisions From Single-Case Designs of Increasing and Decreasing Intensity

There have been several proposals to the effect that special service decisions could be based, at least in part, on the construct of response to intervention and not necessarily on traditional child measures. Single-case designs that focus on intervention response and intensity are reviewed as a potential evaluation framework for interdisciplinary teams to help answer special services resource questions. Increasing-intensity designs are based on sequential intervention trials ordered on a continuum that builds in intensity. Decreasing-intensity designs start with more comprehensive or multicomponent interventions and intervention facets that are systematically withdrawn so that interventions become more natural and ecologically sustainable. The advantages and challenges associated with these designs for use in special education eligibility decisions are discussed as models for child evaluation in schools.